Photometry device

ABSTRACT

A photometry device for a camera is provided with a normal light sensor having a spectral sensitive characteristics close to those of a human eye, and a plurality of colorimetric sensors. The device further includes a photometry value determining system, a calorimetric compensation value determining system that determines a color of an object at each of the plurality of photometry areas and a calorimetric compensation value based on the determined color, and an exposure value determining system that compensates for the photometry value determined by the photometry value determining system for each of the plurality of photometry areas, and determines an exposure value based on the compensated photometry values. In the photometry device configured as above, the calorimetric compensation value determining system determines different colorimetric compensation values for different one of the plurality of photometry areas.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a photometry device applicableto an SLR (Single Lens Reflex) camera, and more particularly to aphotometry device with which exposure errors due to a difference ofreflectivity of objects having different colors can be compensated.

[0002] Recently, reflection type photometry devices have been employedin most of cameras. The reflection type photometry device receives thelight, which is reflected by an object and passed through an observingoptical system of a camera, using a light receiving element, determinesthe brightness of the object based on the output of the measured value,and then calculates the exposure value of the camera based on themeasured brightness.

[0003] However, this type of the photometry device cannot detect thecolor of the object because of its structure. Accordingly, in such adevice, the reflectivity of an object is generally assumed to be 18% andthe exposure parameter is determined on this assumption. Therefore,regarding a whitish object whose reflectivity is greater than 18%, thedetermined brightness is greater than the actual brightness because thedetermined brightness assumes only 18% reflectivity contributing to thebrightness, when the reflectivity contribution is actually higher. Ifthe camera controls an exposure operation based on the determinedexposure value, the object is underexposed. A dark object whosereflectivity is less than 18% is measured to have a lower brightnessthan the actual brightness because the measured brightness assumes 18%reflectivity contributing to the brightness, when the reflectivity isactually lower. Therefore, such an object is over exposed. Thedifference of the reflectivity of the object may also occur depending onthe color of the object. For example, when the color of an object isyellow, the reflectivity may be up to 70%. In such a case, if thestandard reflectivity is assumed to be 18%, the exposure value isapproximately 2 Ev lower than necessary. If the object color is blue,the reflectivity is approximately 9%. In this case, the object is overexposed by approximately 1 Ev greater than necessary.

[0004] Therefore, when the conventional photometry device is used, thephotographer is required to guess the reflectivity of the object. Then,based on the reflectivity determined by the photographer, the exposureis controlled such that, if the object is a whitish or yellowish onehaving a relatively high reflectivity, it is to be overexposed, and ifthe object is a blackish or bluish one having a relatively lowreflectivity, it is to be underexposed. With this operation, theabove-described defects may be solved. However, accurately guessing thereflectivity of the object and controlling the exposure can only be doneby experienced and skilled photographers. It is impossible to requireall the photographers to do such an operation. Further, it is notpreferable that a manual operation of the photographer is required forexposure. Furthermore, if such a manual operation is required, camerasbecome unsuitable for automatic photographing which is the recent trend.

SUMMARY OF THE INVENTION

[0005] It is therefore an object of the invention to provide an improvedphotometry device with which appropriate exposure values can be obtainedwhen the device is configured such that a photographing frame is dividedinto a plurality of areas and calorimetric compensation values, whichare used for compensating an exposure value, are obtained at the dividedareas.

[0006] For the above object, according to the invention, there isprovided a photometry device for a camera, which is provided with anormal light sensor that has a plurality of photometry areas andperforms a photometry operation with respect to an object at each of theplurality of photometry areas, the normal light sensor having a spectralsensitive characteristics close to those of a human eye, a photometryvalue determining system that determines an photometry value at each ofthe plurality of photometry areas in accordance with outputs of thenormal light sensor corresponding to the plurality of photometry areas,a plurality of colorimetric sensors for colorimetry capable ofperforming photometry with respect to each of the plurality ofphotometry areas, the plurality of colorimetric sensors having differentspectral sensitivity characteristics, a colorimetric compensation valuedetermining system that determines a color of an object at each of theplurality of photometry areas in accordance with the outputs of theplurality of calorimetric sensors and determining a colorimetriccompensation value based on the determined color, and an exposure valuedetermining system that compensates for the photometry value determinedby the photometry value determining system for each of the plurality ofphotometry areas, and determines an exposure value based on thecompensated photometry values. In the photometry device configured asabove, the colorimetric compensation value determining system determinesdifferent calorimetric compensation values for different one of theplurality of photometry areas.

[0007] With this configuration, it becomes possible to determineappropriate calorimetric compensation values depending on thearrangement of the areas within a photographing frame.

[0008] In a particular case, the colorimetric compensation valuedetermining system may determine the calorimetric compensation valuessuch that a colorimetric compensation value at a peripheral area of aphotographing frame is smaller than that of a central area of thephotographing frame.

[0009] Alternatively, the colorimetric compensation value determiningsystem may determine the colorimetric compensation values for theplurality of photometry areas depending on a distance of each photometryarea with respect to the center of a photographing frame.

[0010] In such a case, a calorimetric compensation value at an areafarther from the center of the photographing frame may be smaller thanthat at an area closer to the center of the photographing frame.

[0011] Further alternatively, the colorimetric compensation valuedetermining system may determine the colorimetric compensation valuesfor the plurality of photometry areas depending on data intrinsic to aphotographing lens that forms an image of the object.

[0012] In this case, the data intrinsic to the photographing lens mayinclude at least one of a focal length of the photographing lens, anexit pupil position of the photographing lens, and an open f-number ofthe photographing lens.

[0013] Alternatively or optionally, the data intrinsic to thephotographing lens may include a focal length of the photographing lens,and a colorimetric compensation value has a greatest absolute value whenthe focal length is within a predetermined range, the calorimetriccompensation value being smaller when the focal length is greater orsmaller than the predetermined range.

[0014] In this case, the colorimetric compensation value may bedetermined as a function of the focal length.

[0015] Alternatively or optionally, the data intrinsic to thephotographing lens may include an exit pupil position of thephotographing lens, and a calorimetric compensation value has a greatestabsolute value when the exit pupil position is within a predeterminedrange, the colorimetric compensation value being smaller when the exitpupil position is on a front side or rear side with respect to thepredetermined range.

[0016] Also in this case, the colorimetric compensation value may bedetermined as a function of the exit pupil position.

[0017] Still alternatively or optionally, the data intrinsic to thephotographing lens may include an open f-number of the photographinglens, and a colorimetric compensation value has a greatest absolutevalue when the open f-number is within a predetermined range. In thiscase, the colorimetric compensation value may be smaller when the openf-number is smaller or greater than the predetermined range.

[0018] In a particular case, the colorimetric compensation value may bedetermined as a function of the open f-number.

[0019] Further alternatively or optionally, the calorimetriccompensation value determining system may determine the colorimetriccompensation values for the plurality of photometry areas depending onan area corresponding to a part of an object on which a photographinglens is focused.

[0020] In this case, a calorimetric compensation value for an areacorresponding to a part of the object on which the photographing lens isfocused is greater than that for an area corresponding to another partof the object on which the photographing lens is not focused.

[0021] Optionally, the exposure amount determining system may have atleast one of:

[0022] a. a function of determining the exposure amount by performing adivided photometry, based on the compensated photometry values, inaccordance with a predetermined algorithm;

[0023] b. a function of determining the exposure amount by averaging thecompensated photometry values for the plurality of photometry areas;

[0024] c. a function of determining the exposure amount by performingthe center-weighted averaging of the compensated photometry values; and

[0025] d. a function of determining the exposure amount by selecting oneof the compensated photometry values corresponding to the plurality ofareas.

[0026] Further optionally, the normal light photometry sensor and theplurality of calorimetric photometry sensors may be arranged on aneyepiece side of a pentagonal prism of a single lens reflex camera, atleast the normal light photometry sensor being arranged at an uppercentral portion of the pentagonal prism.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[0027]FIG. 1 shows a perspective view of a camera employing a photometrydevice according to the invention;

[0028]FIG. 2 schematically shows main components of the camera shown inFIG. 1;

[0029]FIG. 3A shows an arrangement of photometry sensors;

[0030]FIG. 3B shows an alternative arrangement of photometry sensors;

[0031]FIG. 4A schematically shows a structure of each of the photometrysensors;

[0032]FIG. 4B shows a relationship between the photometry areas of eachphotometry sensor;

[0033]FIG. 5 shows spectral sensitivity characteristics of the green,blue and red light sensors;

[0034]FIG. 6 shows a block diagram of main portions of the camera;

[0035]FIG. 7 is a flowchart illustrating a main procedure of aphotometry operation according to an embodiment;

[0036]FIG. 8 is a flowchart illustrating the “lens communicationprocedure”;

[0037]FIG. 9 shows a flowchart illustrating the “photometry sensor Bvdcalculation procedure”;

[0038]FIG. 10 is a flowchart illustrating the “open aperture photometrycompensation calculation procedure”;

[0039]FIG. 11 is a flowchart illustrating the “colorimetry procedure”;

[0040]FIG. 12 is a flowchart illustrating the “light source compensationprocedure”;

[0041]FIG. 13 is a flowchart illustrating the “light source differencecompensation procedure”;

[0042]FIG. 14 is a flowchart illustrating the “colorimetric parametercalculation procedure”;

[0043]FIG. 15 is a flowchart illustrating the “colorimetric constantssetting procedure”;

[0044]FIG. 16 shows an example of constants read from the EEPROM;

[0045]FIGS. 17 and 18 show a flowchart illustrating the “color judgmentprocedure”;

[0046]FIG. 19 shows the “colorimetric compensation value calculationprocedure”;

[0047]FIG. 20 shows a relationship between types of compensation andfigures illustrating the compensation methods;

[0048]FIG. 21 is a flowchart illustrating an “exposure value (Lvd)calculating procedure”;

[0049]FIG. 22 is a flowchart illustrating an “exposure value determiningprocedure”; and

[0050]FIG. 23 is a flowchart illustrating a “divided photometry Lvdcalculation procedure.”

DESCRIPTION OF THE EMBODIMENTS

[0051] Hereinafter, referring to the accompanying drawings, anembodiment according to the present invention will be described.

[0052]FIG. 1 shows a perspective view of a camera 1000 employing aphotometry device according to the invention, and FIG. 2 schematicallyshows main components of the camera 1000.

[0053] The camera 1000 has a camera body 1, to which a photographinglens 2 is detachably coupled. The camera body 1 accommodates a quickreturn mirror 3, a focusing glass 4, a pentagonal prism 5 (or apentagonal mirror), and an eyepiece optical system 6. A part of thequick return mirror 3 is formed to be a half mirror 3 a (see FIG. 1),and behind the half mirror 3 a, an auxiliary mirror 7 is provided. Lightpassed through the half mirror 3 a is reflected by the auxiliary mirror7, and is directed toward a distance measuring device 8. The distancemeasuring device 8 is configured as a multi-point distance measuringdevice, and an AF (Automatic focusing) control is performed inaccordance with the measurement results of the distance measuring device8.

[0054] On the rear side of the pentagonal prism 5, four photometrysensors 9 (9D, 9R, 9G and 9B) are provided (see FIGS. 1 and 2), each ofwhich functions as a photometry element and receives part of lightpassed through the photographing lens 2. Based on the outputs of thephotometry sensors 9, a photometry operation for determining exposureparameters is executed.

[0055] The photographing lens 2 and the camera body 1 are electricallyconnected through electrical contacts 10. Thus, a lens ROM 11 built inthe photographing lens 2 is electrically connected to a control circuit20 accommodated in the camera body 1. On an outer surface of the camerabody 1, an LCD (liquid crystal display) 21, and various buttons such asa release button 22 and a photometry mode changeover switch 28 areprovided. Furthermore, inside the camera body 1, various mechanisms suchas a film winding mechanism are provided. However, such mechanisms areconventionally known, and description thereof will be omitted for thesake of simplicity.

[0056]FIG. 3A shows a rear view of the pentagonal prism 5. As shown inFIG. 3A, the four photometry sensors 9 includes sensors 9D and 9Gprovided at an upper central portion on the eyepiece side of thepentagonal prism 5, and sensors 9B and 9R are provided at lower sideportions on the eyepiece side of the pentagonal prism 5. The photometrysensors 9D, 9G, 9B and 9R are mounted on an FPC (flexible printedcircuit board) 91 and fixedly positioned at the above-describedrespective positions by the FPC 91. In front of (i.e., on the pentagonalprism side of) each of the photometry sensors 9D, 9G, 9B and 9R, animaging lens 92 is provided to form an object image on each of thesensors 9D, 9G, 9B and 9R (see FIG. 2).

[0057]FIG. 4A schematically shows a structure of each of the sensors 9D,9G, 9B and 9R. As shown in FIG. 4A, each sensor 9 (9D, 9G, 9B or 9R) isconstructed as a planar structure photometry IC chip that is configuredsuch that a light receiving section and an amplifier AMP are integrallyformed. The light receiving section includes six photometry areas, i.e.,a central area A0, a left area A1, a right area A2, an upper area A3, alower area A4, and a peripheral area A5. FIG. 4B shows a relationshipbetween the photometry areas A0-A5 and portions of an object. P0-P2shown in the photometry areas A0-A2 represent distance measuring points,respectively. The photometry areas A0-A5 of each sensor receives thelight from respective portions of an object as indicated in FIG. 4B.

[0058] The photometry sensor 9G is provided with a green filter GF onits light receiving surface, and receives a green component of light,the photometry sensor 9B is provided with a blue filter BF on its lightreceiving surface, and receives a blue component of light, and thephotometry sensor 9R is provided with a red filter RF on its lightreceiving surface, and receives a red component of light. In thisembodiment, the three sensors 9G, 9B and 9R are used as colorimetryelements. Spectral sensitivity characteristics of the sensors 9G, 9B and9R respectively provided with the green, blue and red filters GF, BF andRF are indicated in FIG. 5. The sensors 9G, 9B and 9R have peaks insensitivity at approximately 540 nm, 420 nm, and 620 nm, respectively.

[0059] The remaining sensor 9D is not provided with a color filter, buta sensitivity compensation filter is provided so that the spectralsensitivity characteristic of the sensor 9D has its peak within awavelength range of 500-600 nm, which is close to the visual sensitivitycharacteristic. The sensor 9D is used as a normal light detectingsensor.

[0060]FIG. 6 shows a block diagram of main portions of the camera 1000.The four sensors 9D, 9G, 9B and 9R output values indicative of quantityof received light (components) to the controller 20, respectively.Further, the output (i.e., a distance value) of the distance measuringdevice 8 is transmitted to the controller 20, which controls the AFdevice 25 to perform the automatic focusing operation.

[0061] Furthermore, the controller 20 is connected with a photometryswitch SWS and a shutter-release switch SWR. The photometry switch SWSis ON when the release button 22 is half depressed. The shutter-releaseswitch SWR is ON when the shutter button is fully depressed. When theshutter button 22 is depressed halfway and the photometry switch SWS isturned ON, the controller 20 performs a photometry calculation inaccordance with a predetermined algorithm, and calculates an exposurevalue. Then, the controller 20 controls the exposure control device 23in accordance with the calculated exposure value to perform aphotographing operation. Further, the controller 20 drives a displaydriver 24 to display the calculated exposure value on the LCD panel 21.It should be noted that the controller 20 includes an EEPROM 26 storingvarious values necessary for the photometry calculation (which will bedescribed in detail later), and a RAM 27 for temporarily storing variouspieces of data. Further to the above, when the exposure value isdetermined, a photometry mode signal indicative of one of photometrymodes (e.g., area-divided photometry, averaged photometry, central areaweighted photometry, a spot photometry and the like) is transmitted fromthe photometry mode changeover switch 28 to the controller 20.

[0062] An operation of the photometry device will be describedhereinafter.

[0063] A procedure shown in FIG. 7 is a main procedure of a photometryoperation. When the release button 22 is half depressed and thephotometry switch SWS is ON (S11: YES), a “lens communication procedure”is performed (S12) so that the controller 20 receives data intrinsic tothe photographing lens 2 currently mounted onto the camera body 1.Specifically, the data intrinsic to the photographing lens 2 includes anopen f-number (full aperture), a focal length of the photographing lens2, an exit pupil position and the like, which may affect the photometrycalculation. The data is transmitted from a lens ROM 11 of thephotographing lens 2 to the controller 20 through the electricalcontacts 10. In S12A, a distance measuring operation is performed withrespect to the distance measuring points P0-P2. Then, a “photometrysensor output Bvd calculation procedure” is executed (S13). In thisprocedure, the photometry sensors 9 (9D, 9G, 9B and 9R) output analogphotometry values which are obtained by receiving light through thephotographing lens 2, the quick return mirror 3, and the pentagonalprism 5. Then, the analog values are converted into digital brightnessvalues Bvd which can be used in the operation executed by the controller20.

[0064] It should be noted that the photometry is performed for each ofthe photometry areas A0-A5, and photometry values Bvd(i) (i beingintegers 0-5 corresponding to the photometry areas A0-A5). Then, usingthe photometry values Bvd(i) obtained in S13 and the data intrinsic tothe photographing lens 2 obtained in S12, an “open aperture photometrycompensation calculation procedure” is performed in S14, therebyindividual photometry errors depending on the photographing lens 2 beingcanceled.

[0065] At S15, based on the brightness values Bvd(i) corresponding tothe sensors 9R, 9B and 9G for the RGB (Red, Green and Blue) colorcomponents, a “colorimetry procedure” is executed to determine the colorof an object for each of the photometry areas A0-A5. Then, for each ofthe photometry areas A0-A5, a calorimetric compensation value CC(i) iscalculated based on the determined color of the object by executing an“calorimetric compensation value calculation procedure.” In S17, an“exposure value calculating procedure” is executed, where thecalorimetric compensation values CC(i) are added to the photometryvalues Bvd(i), respectively, and an exposure value Lvd for each of thephotometry areas A0-A5 is obtained based on the compensated photometryvalues Bvd(i). In the exposure value calculation procedure (S17), inaccordance with the photometry mode set by the photometry modechangeover switch 28, a calculation method is determined, and then,based on the photometry values Bvd(i), the exposure value Lvd iscalculated using the determined calculation method.

[0066] At S18, if the shutter-release switch SWR is ON (S18: YES), theexposure control device 23 controls the exposure operation at S20 inaccordance with the exposure value Lvd obtained at S17 to execute aphotographing operation. If the shutter-release switch SWR is OFF,controls goes to S19, where it is detected whether a photometry timer isOFF.

[0067] If the photometry timer is ON (i.e., if a predetermined periodhas not elapsed) (S19: NO), control proceeds to S12, and the foregoingprocedures are repeated. If the photometry timer is OFF (i.e., if thepredetermined period has elapsed) (S19: YES), control proceeds to S11.

[0068]FIG. 8 is a flowchart illustrating the “lens communicationprocedure”, which is called at S12 of the main procedure shown in FIG.7.

[0069] In the lens communication procedure, the controller 20 accessesthe lens ROM 11 through the electrical contacts 10, and retrieves thedata intrinsic to the photographing lens 2 stored in the lens ROM 11(S101). The retrieved data is stored in the RAM 27 of the controller 20,and control returns. Items included in the data intrinsic to thephotographing lens 2 include, for example, a lens type, lens data, theshortest focusable distance, a focusable range, a focal length of thephotographing lens, an exit pupil position, an open f-number, anaperture efficiency and the like. In this embodiment, the controller 20reads at least the focal length, the exit pupil position, the openf-number and the aperture efficiency, and stores the data in the RAM 27.

[0070]FIG. 9 shows a flowchart illustrating the “photometry sensor Bvdcalculation procedure”, which is called at S13 in the main procedureshown in FIG. 7.

[0071] In this procedure, digital data values Bvad(i) (where, i=0, 1, .. . , 5) which represents A/D converted output voltages (analog data) ofthe photometry areas Ai (i=0, 1, . . . , 5) shown in FIG. 4A of thephotometry sensor 9D for normal light are obtained. Further,dataBvad·g(i), Bvad·b(i) and Bvad·r(i) which represent A/D convertedvalues of the output voltages of the photometry areas Ai (i=0, 1, 2, . .. 5) of each of the sensors 9G, 9B and 9R for color components areobtained. Then, the A/D converted values Bvad(i) of the sensor 9D outputare adjusted to brightness values Bvd(i) (S111). The A/D convertedvalues Bvad·g(i), Bvad·b(i) and Bvad·r(i) (i=0, 1, 2, . . . 5) are alsoadjusted to the brightness values Bvd·g(i), Bvd·b(i) and Bvd·r(i),respectively (S112). It should be noted that the A/D conversion methodemployed in S111 and S112 is a well-known method for converting aquantity of analogue value into digital data, and therefore, descriptionthereof is not given herein.

[0072]FIG. 10 is a flowchart illustrating the “open aperture photometrycompensation calculation procedure” which is called at S14 of the mainprocedure shown in FIG. 7.

[0073] At S121, an open aperture photometry compensation value Mnd1 (i)is calculated based on the focal length, the exit pupil position, theopen f-number and the aperture efficiency which have been retrieved fromthe ROM 11 and stored in the RAM 27.

[0074] The open aperture photometry compensation values Mnd1(i) areobtained as follows. Firstly, compensation values mv1, mv2, mv3 and mv4for compensating for shift amounts with respect to the referencephotometry values due to the individual differences of the opticalcharacteristics of the cameras, and the focal length, the exit pupilposition, the open f-number and the aperture efficiency, are determined.Then, the sum of the compensation values mv1+mv2+mv3+mv4 is obtained,which sum is referred to as the open aperture compensation valueMnd1(i). Similarly, corresponding to the photometry sensors 9G, 9B and9R, the open aperture compensation values Mnd1·g(i), Mnd1·b(i), andMnd1·r(i) are calculated. Then the open aperture compensation value Mnd1(i) is added to the brightness value Bvd(i), and then the sum isdetermined as a new brightness value Bvd(i). Thus, the followingcalculation is executed at S121:

Bvd(i)=Bvd(i)+Mnd1(i).

[0075] Similar to the above, with respect to the brightness valuesBvd·g(i) , Bvd·b(i) and Bvd·r(i) obtained by the photometry sensors 9G,9B and 9R, open aperture photometry compensation values Mnd1·g(i),Mnd1·b(i) and Mnd1·r(i) are added to obtain newly defined brightnessvalues (S122). That is:

Bvd·g(i)=Bvd·g(i)+Mnd1·g(i).

Bvd·b(i)=Bvd·b(i)+Mnd1·b(i).

Bvd·r(i)=Bvd·r(i)+Mnd1·r(i).

[0076] As a result, each brightness value is free from the affect of theindividual differences of photographing lenses 2 coupled to the camerabody 1.

[0077] At S15 of the main procedure shown in FIG. 7, a “colorimetryprocedure” is called, which is shown in FIG. 11. In the “colorimetryprocedure”, the color of the object is detected, and in S16, the“colorimetry procedure” is called and colorimetric compensation valuesCC(i) are calculated in accordance with the detected color of theobject.

[0078]FIG. 11 is a flowchart illustrating the “colorimetry procedure”called at S16 of the main procedure.

[0079] At S21, colorimetric parameters are initialized (i.e. set toinitial values). At S22, a “light source compensation procedure” isexecuted to obtain compensation values for the effects of the colortemperature of the light source. At S23, a “light source differencecompensation procedure” is executed using the compensation valuesobtained at S22. At S24, a “colorimetric parameter calculationprocedure” for obtaining calorimetric parameters, which will be used forexecution of a “colorimetric judgment procedure”, is executed. At S25, a“colorimetric constants setting procedure” is executed to set constantsused for color measurement. At S26, a “color judgment procedure” forjudging a color based on the parameters and constants obtained in thepreceding steps is executed.

[0080]FIG. 12 shows a flowchart illustrating the “light sourcecompensation procedures” called at S22 of FIG. 11.

[0081] In the embodiment, when the initial Bvd value of the photometrysensors 9 is determined, a predetermined light source (light source A)is used. When a photographing is to be executed, the Bvd should becompensated in accordance with the actually used light source, forexample, the sunlight. In the procedure shown in FIG. 12, relativecompensation values of B (blue) and R (red) components with respect tothe value for the G (green) component are obtained, and the compensationis performed.

[0082] Specifically, for the color components G, B and R, the brightnessdata Bvd·light·g, Bvd·light·b, and Bvd·light·r, are retrieved from theEEPROM 26 (S141). Then, a light source adjustment value adj·sun·b forthe photometry sensor 9B and a light source adjustment value adj·sun·rfor the photometry sensor 9R with respect to the value for G componentare retrieved from the EEPROM 26 (S142). The light source adjustmentvalues are as follows.

adj·sun·b=+8

adj·sun·r=−4

[0083] It should be noted that, if the adjustment of the sensors 9 isexecuted using the sun light instead of the predetermined light sourceA, the light source adjustment values are all zero.

[0084] Then, based on the brightness data and the light sourceadjustment values, a light source compensation value light·gb for thephotometry sensor 9B is obtained as follows (S143).

light·gb=Bvd·light·g−Bvd·light·b+adj·sun·b

[0085] Similarly, a light source compensation value light·gr for thephotometry sensor 9R is obtained as follows (S144).

light·gr=Bvd·light·g−Bvd·light·r+adj·sun·r

[0086]FIG. 13 is a flowchart illustrating the “light source differencecompensation procedure”, which is called at S23 in FIG. 11. In thisprocedure, based on the light source compensation values for light·gband light·gr, the light source compensation is applied to the brightnessvalues Bvd·b(i) and Bvd·r(i) (i=0-5) obtained at areas A0-A5 of thephotometry sensors 9B and 9R, respectively.

[0087] At S151, for each photometry area of the photometry sensor 9B,the following calculation is executed.

Bvd·b(i)=Bvd·b(i)+light·gb.

[0088] At S152, for each photometry area of the photometry sensor 9R,the following calculation is executed.

Bvd·r(i)=Bvd·r(i)+light·gr.

[0089] With the above compensation, the photometry sensors 9G, 9B and 9Rhas the same photometric characteristics for the external light sourcesuch as the sunlight.

[0090]FIG. 14 is a flowchart illustrating the “colorimetric parametercalculation procedure”, which is called at S24 of FIG. 11. In thisprocedure, colorimetric parameters used in the colorimetric judging arecalculated. As the calorimetric parameters, parameters Gf(i) for Gcomponent, parameters Bf(i) for B component, and parameters Rf(i) for Rcomponent are calculated (S161, S162 and S163) according to thefollowing formulae.

Gf(i)=Bvd·g(i)−{Bvd·b(i)+Bvd·r(i)}/2;

Bf(i)=Bvd·b(i)−{Bvd·g(i)+Bvd·r(i)}/2; and

Rf(i)=Bvd·r(i)−{Bvd·b(i)+Bvd·g(i)}/2.

[0091]FIG. 15 is a flowchart illustrating the “colorimetric constantssetting procedure”, in which the colorimetric constants are retrievedfrom the EEPROM 26. The colorimetric constants include: threshold valuesfor color judgment; coefficients for color judgment; coefficients forcalculating colorimetric compensation values; and adjustment values forcalculating the colorimetric compensation values, which are representedby valuables as indicated below:

[0092] threshold values for color judgment: THvalue·*1(i);

[0093] coefficients for color judgment: coefficient·#1(i) andcoefficient·#2(i);

[0094] coefficients for calculating colorimetric compensation values:CCcoefficient·*1(i);

[0095] adjustment values for calculating the colorimetric compensationvalues: CCadjestment·*1(i).

[0096] In the above indication, a symbol * represents g (green), b(blue), r (red), m (magenta), y (yellow) or c (cyan), and a symbol #represents g (green), b (blue) or r (red).

[0097] In this procedure, for all the photometry areas A0-A5 of thesensors 9, the colorimetric constants are set, respectively. Therefore,at S171, i is set to zero (0), and then, if i≦5 (S172: YES), theconstants are read from the EEPROM (S173, S174, S175 and S176). Then, atS177, i is incremented by one, and control returns to S172. Thus, fori=0 through 5, steps S173-S176 are repeated. The constants read from theEEPROM 26 are stored in the RAM 27 of the controller 20. FIG. 16 showsan example of the constants read from the EEPROM 26.

[0098]FIGS. 17 and 18 show a flowchart illustrating the “color judgmentprocedure”. The procedure judges the color of the object for eachphotometry area A0-A5.

[0099] At S181, i is set to 0. Then, if i≦5 (S182: YES), the followingsteps are repeated. In the following description, Color(i) representscolor parameters, and Color·max(i) and Color·min(i) represent colorjudgment parameters.

[0100] At S183, the color parameter Color(i) is set to colorless. Then,at S184, Rf(i) and THvalue·c1(i) are compared.

[0101] If Rf(i)<THvalue·c1(i) (S184:YES), |Bf(i)−Gf(i)| and|coefficient·r1(i)×Rf(i)| are compared (S185).

[0102] If |Bf(i)−Gf(i)|<|coefficient·r1(i×Rf(i)| (S185:YES),Color·min(i) is set to Rf(i) (S186).

[0103] If Rf(i)≧THvalue·c1(i) (S184:NO) or|Bf(i)−Gf(i)|≧|coefficient·r1(i)×Rf(i)| (S185:NO), step S186 is skipped.

[0104] At S187, Gf(i) is compared with THvalue·m1(i).

[0105] If Gf(i)<THvalue·m1(i) (S187:YES), |Bf(i)−Rf(i)| and|coefficient·g1(i)×Gf(i)| are compared (S188).

[0106] If |Bf(i)−Rf(i)|<|coefficient·g1(i)×Gf(i)| (S188:YES),Color·min(i) is set to Gf(i) (S189).

[0107] If Gf(i)≧THvalue·m1(i) (S187:NO) or|Bf(i)−Rf(i)|≧|coefficient·g1(i)×Gf(i)| (S188:NO), step S189 is skipped.

[0108] At S190, Gf(i) is compared with THvalue g1(i).

[0109] If Gf(i)>THvalue·g1(i) (S190:YES), |Bf(i)−Rf(i)| and|coefficient·g2(i)×Gf(i)| are compared (S191).

[0110] If |Bf(i)−Rf(i)|<|coefficient·g2(i)×Gf(i)| (S191:YES),Color·max(i) is set to Gf(i) (S192).

[0111] If Gf(i)≦THvalue·g1(i) (S190:NO) or|Bf(i)−Rf(i)|≧|coefficient·g2(i)×Gf(i)| (S191:NO), step S192 is skipped.

[0112] At S193, Bf(i) is compared with THvalue·b1(i).

[0113] If Bf(i)>THvalue·b1(i) (S193:YES), |Gf(i)−Rf(i)| and|coefficient·b2(i)×Bf(i)| are compared (S194).

[0114] If |Gf(i)−Rf(i)|<|coefficient·2(i)×Bf(i)| (S194:YES),Color·max(i) is set to Bf(i) (S195). If Bf(i)≦THvalue·b1(i) (S193:NO) or|Gf(i)−Rf(i)|≧|coefficient·b2(i)×Bf(i)| (S194:NO), step S195 is skipped.

[0115] At S196, Rf(i) is compared with THvalue·r1(i).

[0116] If Rf(i)>THvalue·r1(i) (S196:YES), |Bf(i)−Gf(i)| and|coefficient·r2(i)×Rf(i)| are compared (S197).

[0117] If |Bf(i)−Gf(i)|<|coefficient r2(i)×Rf(i)| (S197:YES),Color·max(i) is set to Rf(i) (S198). If Rf(i)≦THvalue·r1(i) (S196:NO) or|Bf(i)−Gf(i)|<|coefficient·r2(i)×Rf(i)| (S197:NO), step S198 is skipped.

[0118] At S199, Bf(i) is compared with THvalue·y1(i).

[0119] If Bf(i)<THvalue·y1(i) (S199:YES), |Gf(i)−Rf(i)| and|coefficient·b1(i)×Bf(i)| are compared (S200).

[0120] If |Gf(i)−Rf(i)|<|coefficient·b1(i)×Bf(i)| (S200:YES),Color·min(i) is set to Bf(i) (S201). If Bf(i)·THvalue·y1(i) (S199:NO) or|Gf(i)−Rf(i)|≧|coefficient·b1(i)×Bf(i)|(S200:NO), step S201 is skipped.

[0121] During the above steps, for each of the photometry areas A0-A5,color·max(i) and color·min(i) are obtained.

[0122] At S202 (FIG. 18), it is jedged whether color·min(i) is equal toRf(i). If color·min(i) is equal to Rf(i) (S202:YES), color(i) is set tocyan (S203). If color·min(i) is not equal to Rf(i), S203 is skipped.Then, it is judged whether color min(i) is equal to Gf(i) at S204. Ifcolor·min(i) is equal to Gf(i) (S204:YES), color(i) is set to magenta(S205). If color·min(i) is not equal to Gf(i), S205 is skipped. Next, itis judged whether color·max(i) is equal to Gf(i) at S206. Ifcolor·max(i) is equal to Gf(i) (S206:YES), color(i) is set to green(S207). If color·max(i) is not equal to Gf i) (S206:NO), S207 isskipped. In S208, it is judged whether color·max(i) is equal to Bf(i).If color·max(i) is equal to Bf(i), color (i) is set to blue (S209). Ifcolor·max(i) is not equal to Bf(i) (S208:NO), then S209 is skipped. InS210, it is judged whether color·max(i) is equal to Rf(i). Ifcolor·max(i) is equal to Rf(i) (S210:YES), then color(i) is set to red(S211). If color·max(i) is not equal to Rf(i) (S210:NO), S211 isskipped. In S212, it is judged whether color·min(i) is equal to Bf(i).If color·min(i) is equal to Bf(i) (S212:YES), color(i) is set to yellow(S213), and control proceeds to S214. If color·min (i) is not equal toBf(i) (S212:NO), step S213 is skipped, and control proceeds to S214,where i is incremented by one. Then, control proceeds to S182. As aresult of the above-described procedure, yellow has the highestpriority, and in the foregoing steps, the color finally selected inaccordance with the conditions is determined as the color of thephotometry area. Since the above procedure is repeated for i=0 to i=5,the color of each of the photometry areas A0-A5 is determined.

[0123] After the color judgment is performed as described above, the“calorimetric compensation value calculation procedure” as shown in FIG.19 is called at S16 of the flowchart shown in FIG. 7.

[0124] In this procedure, the colorimetric compensation values CC(i)corresponding to the difference of the colors among the photometry areasare calculated.

[0125] At S221, i is set to an initial value of zero. At S222, it isjudged whether i is equal to or smaller than five, or greater than five.If i is 0, 1, 2, 3, 4 or 5, (S222:YES), it is judged whether color(i) iscolorless (S223). If color(i) is colorless (S223:YES), CC(i) is set tozero (S224). If color(i) is not colorless (S223:NO), step S224 isskipped. At S225, it is judged whether color(i) is cyan. If color(i) iscyan (S225:YES), the colorimetric compensation value CC(i) is set to Cin S226. If color(i) is not cyan (S225:NO), then step S226 is skipped.

[0126] At S227, it is judged whether color(i) is magenta. If color( i)is magenta (S227: YES), the colorimetric compensation value CC(i) is setto M in S228. If color(i) is not magenta (S227:NO), then step S228 isskipped.

[0127] At S229, it is judged whether color(i) is green. If color(i) isgreen (S229:YES), the calorimetric compensation value CC(i) is set to Gin S230. If color(i) is not green (S229:NO), then step S230 is skipped.

[0128] At S231, it is judged whether color(i) is blue. If color(i) isblue (S231 YES), the colorimetric compensation value CC(i) is set to Bin S232. If color(i) is not blue (S231:NO), then step S232 is skipped.

[0129] At S233, it is judged whether color(i) is red. If color(i) is red(S233:YES), the colorimetric compensation value CC(i) is set to R inS234. If color(i) is not red (S233:NO), then step S234 is skipped.

[0130] At S235, it is judged whether color(i) is yellow. If color(i) isyellow (S235:YES), the colorimetric compensation value CC(i) is set to Yin S236. If color(i) is not yellow (S235:NO), then step S236 is skipped.Then, at S237, i is incremented by one, and control returns to S222. Bythe above procedures for i=0 to i=5, each of the calorimetriccompensation values CC(i) is set to Y, M, C, B, G or R.

[0131] In the following procedure, for the determined values of Y, M, C,B, G or R for each of the calorimetric compensation values CC(i), anumerical value is assigned to obtain a numerical value of thecolorimetric compensation value CC(i). FIG. 20 shows a relationship ofconditions (A) through (E) for compensation, and TABLEs indicating thenumerical values.

[0132] As understood from FIG. 20, there are conditions in which thecompensation of the colorimetric compensation values is performed ornot. The latter condition is indicated as condition (A) in FIG. 20. Theformer is further divided into four conditions, which include:

[0133] condition (B) where the colorimetric compensation values, whichare modified in accordance with a distance from the center of thephotographing frame, are selected, or the calorimetric compensationvalues are calculated in accordance with a distance from the center ofthe photographing frame;

[0134] condition (C) where the colorimetric compensation values, whichare modified in accordance with the data intrinsic to the photographinglens, are selected;

[0135] condition (D) where the calorimetric compensation values arecalculated in accordance with the data intrinsic to the photographinglens; and

[0136] condition (E) where the colorimetric compensation values, whichare modified in accordance with the focusing condition data, areselected.

[0137] TABLE 1 shows the colorimetric compensation values correspondingto the symbols Y, M, C, B, G and R, which are stored in the EEPROM 27.TABLE 1 Symbol colorimetric compensation value Y −8 M  0 C  0 B +6 G  0R +2

[0138] It should be noted that the values shown in TABLE 1 are defaultvalues, which are used when the modification or calculation as inconditions (B)-(E) will not be performed.

[0139] TABLE 2 indicates the colorimetric compensation values which aremodified in accordance with the distance with respect to the center ofthe photographing frame. The values indicated in TABLE 2 are stored inthe EEPROM 27. TABLE 2 colorimetric compensation values Symbol 0 ≦ Yd <2.5 2.5 ≦ Yd < 8.5 8.5 ≦ Yd Y −8 −4 −2 M  0  0  0 C  0  0  0 B +6 +3 +1G  0  0  0 R +2 +1  0

[0140] A relationship between the photometry areas A0-A5 and thedistance Yd from the center of the photographing frame is indicated inTABLEs 3 and 4. The relationship shown in TABLEs 3 and 4 is stored inthe EEPROM 27. TABLE 3 longer side Yd (mm) photometry area   0 ≦ Yd ≦2.5 A0 2.5 ≦ Yd < 8.5 A1, A2 8.5 ≦ Yd A5

[0141] TABLE 4 shorter side Yd (mm) photometry area   0 ≦ Yd ≦ 2.5 A02.5 ≦ Yd < 5.6 A3, A4 5.6 ≦ Yd A5

[0142] It should be noted that, for the photometry area AS, the value inTABLE 3 or TABLE 4 is selected depending on the side along which theimage is formed.

[0143] When the colorimetric compensation value is assigned to eachphotometry area A(i) ,the distance Yd is determined based on TABLEs 3and 4, and then an appropriate value indicated in TABLE 2 is selected.

[0144] TABLE 5 indicates alternative modification of the calorimetriccompensation values, which may also be stored in the EEPROM 27. In TABLE5, the calorimetric compensation values are provided by a function ofYd. TABLE 5 Symbol colorimetric compensation values Y  Yd − 10 (Y ≦ 0) M 0 C  0 B −Yd/2 + 6 (B ≧ 0) G  0 R −Yd/3 + 3 (R ≧ 0)

[0145] In the embodiment, the amount (i.e., the absolute value) of thecalorimetric compensation value is smaller for a farther point. Forexample, in TABLE 2, the value of Y is −8 for 0≦Yd<2.5, is −4 for2.5≦Yd<8.5, and is −2 for 8.5<Yd. Further, the values for M, C and R arefixed to zero.

[0146] TABLE 6 shows the calorimetric compensation values for condition(C). In this example, as the data intrinsic to the photographing lens 2,the exit pupil position, the open f-number, and the focal length arereferred to. Depending on the data intrinsic to the photographing lens,one of columns A, B and C in TABLE 6 is selected. TABLE 6 colorimetriccompensation values Symbol A B C Y −8 −4 −2 M  0  0  0 C  0  0  0 B +6+3 +1 G  0  0  0 R +2 +1  0

[0147] TABLEs 7-9 show which of the columns A-C of TABLE 6 is to beselected depending on the exit pupil, open f-number and focal length,respectively. The conditions indicated in TABLEs 7-9 are stored in theEEPROM 26. TABLE 7 Exit Pupil position (1/Exp) selected column Exitp <40 C  40 ≦ Exitp < 60 B  60 ≦ Exitp < 120 A 120 ≦ Exitp < 200 B 200 ≦Exitp C

[0148] TABLE 8 Open f-number selected column Avmin < 1.5 C 1.5 ≦ Avmin <2.5 B 2.5 ≦ Avmin < 3.5 A 3.5 ≦ Avmin < 4.5 B 4.5 ≦ Avmin C

[0149] TABLE 9 Focal Length (mm) selected column FL < 24 C  24 ≦ FL < 40B  40 ≦ FL < 100 A 100 ≦ FL < 300 B 300 ≦ FL C

[0150] As understood from the TABLEs 6-9, values for M, C and G are setto a fixed value of zero. For Y, B and R, when the exit pupil position,the open f-number or the focal length has a central value, colorimetriccompensation values having the greatest absolute values are selected,and when the exit pupil position, the open f-number or the focal lengthdecreases or increased with respect to the central value, thecolorimetric compensation values having smaller absolute values areselected.

[0151] TABLEs 10-12 show the calorimetric compensation values forcondition (D). In this example, as the data intrinsic to thephotographing lens 2, the exit pupil position, the open f-number, andthe focal length are referred to. Depending on the data intrinsic to thephotographing lens, the calorimetric compensation values are calculated.It should be noted that the coefficients of the formulae shown in TABLEs10-12 are stored in the EEPROM 26.

[0152] TABLE 10 shows a relationship between the colorimetriccompensation values and the exit pupil position Exitp. As indicated inTABLE 10, depending on whether the exit pupil position is greater than80 or not, Y, B and R are calculated in accordance with differentformulae. The values for M, C and G are fixed to zero. TABLE 10colorimetric compensation value Symbol Exitp ≦ 80 80 < Exitp Y −0.1 ×Exitp (Y ≦ 0)  0.05 × Exit − 12 (Y ≦ 0) M  0  0 C  0  0 B  0.1 × Exitp −2 (B ≧ 0) −0.05 × Exitp + 10 (B ≧ 0) G  0  0 R  0.05 × Exitp − 2 (R ≧ 0)−0.05 × Exitp + 6 (R ≧ 0)

[0153] TABLE 11 shows a relationship between the colorimetriccompensation values and the open f-number Avmin. As indicated in TABLE11, depending on whether the Avmin is greater than 3 or not, Y, B and Rare calculated in accordance with different formulae. The values for M,C and G are fixed to zero. TABLE 11 colorimetric compensation valueSymbol Avmin ≦ 3 3 < Avmin Y −2 × Avmin − 2  2 × Avmin − 14 (Y ≦ 0) (Y ≦0) M 0 0 C 0 0 B 2 × Avmin (B ≧ 0) −2 × Avmin + 12 (B > 0) G 0 0 R Avmin− 1 (R ≧ 0) −1 × Avmin + 5 (R ≧ 0) 

[0154] TABLE 12 shows a relationship between the colorimetriccompensation values and the focal length FL. As indicated in TABLE 12,depending on whether FL is greater than 50 or not, Y, B and R arecalculated in accordance with different formulae. The values for M, Cand G are fixed to zero. TABLE 12 colorimetric compensation value SymbolFL ≦ 50 50 < FL Y −0.15 × FL − 0.5 (Y ≦ 0) 0.05 × FL − 10.5 (Y ≦ 0) M 00 C 0 0 B 0.1 × FL + 1 (B ≧ 0) −0.05 × FL + 8.5 (B > 0) G 0 0 R 0.05 ×FL − 0.5 (R ≧ 0) −0.05 × FL + 4.5 (R ≧ 0)

[0155] It should be noted that the values calculated in accordance withthe above formulae are close to the values obtained in accordance withcondition (C) with reference to TABLE 6.

[0156] TABLE 13 shows the colorimetric compensation values for condition(E). In this example, depending on the focusing condition, thecolorimetric compensation values are selected. It should be noted thatthe coefficients of the values shown in TABLE 13 are stored in theEEPROM 26.

[0157] In the camera according to the embodiment, distance measuringpoints P0, P1 and P3 are provided, which correspond to the photometryareas A0, A1 and A2. In TABLE 13, depending on whether the photometryareas A0, A1 and A2 are focused or not, the calorimetric compensationvalues for Y, B and R are selected. The values for M, C and G are fixedto zero. TABLE 13 colorimetric compensation value area A0 areas A1 andA2 Symbol focused not focused focused Not focused Y −8 −4 −6 −2 M 0 0 00 C 0 0 0 0 B +6 +3 +4 +2 G 0 0 0 0 R +2 +1 +1 +1

[0158] As understood from TABLE 13, the colorimetric compensation valuesfor Y, B and R are smaller when the areas A1 and A2 are focused than acase where the area A0 is focused. The calorimetric compensation valuesfor M, C and G are fixed to zero.

[0159] After the color compensation values CC(i) are set as describedabove (S16 in FIG. 7), an “exposure value calculation procedure” isexecuted.

[0160]FIG. 21 is a flowchart illustrating the “exposure valuecalculating procedure”, which is called at S17 of the main procedureshown in FIG. 7. The “exposure value calculation procedure” is aprocedure for obtaining a suitable exposure value Lvd by applyingcompensation based on a photographing condition to the brightness valuesBvd(i) for the photometry areas A0-A5 of the normal light sensor 9D,which are obtained in S13 and compensated in S14 (FIG. 7). Specifically,in this procedure, for example, by comparing the brightness valuesBvd(i) with each other or by evaluating the brightness values Bvd(i) asa whole, a photographing conditions, e.g., a rear light photographing, amagnification and/or scene of photographing, is judged. Then, based onthe photographing condition as judged, the exposure value Lvd iscalculated by applying a predetermined algorithm with respect to thebrightness values Bvd(i). For example, the exposure value Lvd suitableto the photographing condition may be determined by weighted-averagingthe brightness values Bvd(i), or by selecting one of the brightnessvalues Bvd(i).

[0161] In S131, a calorimetric compensation calculation is executed. Inthe colorimetric compensation calculation, colorimetric compensationvalues CC(i) for the photometry areas A0-A5 are added to the brightnessvalues Bvd(i)f or the photometry areas A0-A5, respectively, to obtainthe compensated brightness values Bvd(i). That is:

Bvd(i)=Bvd(i)+CC(i)

[0162] Then, in accordance with the setting of the photometry modeselection switch 28, a photometry mode flag is set (S132). At S133, an“exposure value calculation procedure” is executed to calculate theexposure value Lvd in accordance with the photometry mode represented bythe photometry mode flag.

[0163]FIG. 22 shows a flowchart illustrating the “exposure valuecalculation procedure” which is called at S133 of the flowchart shown inFIG. 21.

[0164] In S301, the photometry mode flag is checked. Depending on thephotometry mode flag, control diverges to one of S302, S303, S304 andS305. Specifically, when the photometry mode flag represents the dividedphotometry, control proceeds to S302 and a divided-photometry exposurevalue Lvd is calculated. If the photometry mode flag represents theaveraging photometry, control proceeds to S303 and anaveraged-photometry exposure value Lvd is calculated. If the photometrymode flag represents the center-weighted photometry, control proceeds toS304 and a center-weighted photometry exposure value Lvd is calculated.If the photometry mode flag represents the spot photometry, controlproceeds to S305 and a spot photometry exposure value Lvd is calculated.

[0165]FIG. 23 shows a flowchart illustrating a “divided-photometryexposure value calculation procedure”, in which the exposure value Lvdis determined based on the compensated brightness values Bvd(i).Firstly, based on the compensated brightness values Bvd(i) for thephotometry areas A0-A5 of the sensor 9D, parameters for calculating theexposure value Lvd is obtained (S311). Then, the parameters arecompensated based on an upper limit of the brightness (S312), a rearlight condition (S313), weighted parameter calculation (S314), aphotographing magnification (S315), a photographing scene (S316), apositive compensation for the high brightness photographing scene(S317). Then, based on the compensated parameters, the exposure valueLvd is obtained (S318).

[0166] When the averaged-photometry exposure value is obtained at S303of FIG. 22, the exposure value Lvd is calculated merely by averaging thebrightness values Bvd(i) as follows:

Lvd={Bvd(0)+Bvd(1)+Bvd(2)+Bvd(3)+Bvd(4)+Bvd(5)}/6

[0167] When the center-weighted exposure value is obtained at S304 ofFIG. 22, the exposure value Lvd is calculated based on the followingformula:

Lvd={(Bvd(0)×4)+Bvd(5)+(Bvd(1)+Bvd(2)+Bvd(3)+Bvd(4))×¾}/8

[0168] When the spot-photometry exposure value is obtained at S305 ofFIG. 22, the maximum value of the brightness values Bvd(i) is selected.That is:

Lvd=max {Bvd(0), Bvd(1), Bvd(2), Bvd(3), Bvd(4), Bvd(5)}

[0169] Alternatively, the brightness value Bvd(0) of the centralphotometry area A0 may be used as the exposure value Lvd.

[0170] If the thus calculated exposure value Lvd is input to a not-shownexposure control device, which controls the exposure operation of thecamera, an object can be photographed at an appropriate exposure valueregardless of the difference of colors (i.e., the difference of thereflectivity).

[0171] Specifically, when the object color is determined to be yellow,the exposure compensation value is determined so that the object isoverexposed, and when the object color is determined to be blue or red,the exposure compensation value is determined so that the object isunderexposed. Thus, the difference of reflectivity depending on thecolor of the object can be resolved, and an appropriate exposure can beperformed.

[0172] According to the above-described embodiment, each of thephotometry sensor for the normal light, and those for the colorimetryhas a plurality of photometry areas, and the exposure value iscalculated based on the compensated photometry values. In particular,the colorimetric compensation value obtained by the calorimetricjudgment in each photometry area is modified depending on the distancefrom the center of the photographing frame, the exit pupil position, theopen f-number, the focal length, the photographing condition at aphotometry area corresponding to the distance measuring area.

[0173] With this configuration, the calorimetric compensation values ofyellow, blue and red, which greatly affects the exposure value, aremodified such that, for example, the calorimetric compensation values atthe peripheral areas are smaller that those at the central areas,thereby the effects of the color of an object located at the peripheralportion of the photographing frame are reduced, and a central part ofthe object is appropriately exposed. Thus, the effects of the erroneouscompensation due to the inferior photometry accuracy at the peripheralportion are eliminated with this configuration. It should be noted that,in the above-described embodiment, compensation corresponding to the G,M and C components are not provided since these components have lesseffect to the exposure value.

[0174] In the above-described embodiment, as shown in FIG. 3A, thesensor 9D for the normal light is arranged at an upper central potion onthe eyepiece side of the pentagonal prism 5. Thus, with respect to theobject, the sensor 9D for the normal light is arranged at thesymmetrically central position. Therefore, it becomes possible to setthe photometry sensitivity distribution of the sensor 9D is madesymmetrically with respect to the center thereof, and obtain highphotometry accuracy at the central area of the pentagonal prism 5, whicharea has a higher priority in photometry operation. That is, at thecenter of the pentagonal prism 5, a difference of angles formed betweenthe optical axis of the photographing lens 2 and the optical axis of theeyepiece optical system 5 can be made small. Therefore, a substantiallyall the photographing angle range can be covered using the sensor 9D forthe normal light.

[0175] In the above-described embodiment, the sensor 9D for the normallight is provided in addition to the sensors 9B, 9G and 9R for B, G andR color components. The light receiving characteristics of the sensor Ghas a peak at the wavelength of 540 nm. This characteristic is close tothat of the sensor 9D. Therefore, in another embodiment of theinvention, the sensor 9G is used instead of the sensor 9D, and thesensor 9D is omitted, as shown in FIG. 3B. In such a case, in stepsS11-S15 of the main procedure (FIG. 7), the output Bvad·g of the sensor9G is used as Bvad, and the calculation is to be executed.

[0176] With this configuration, the photometry device includes onlythree photometry sensors. Since the number of the sensors is reduced,such a structure contributes to reduction of the manufacturing cost.Further, the omission of one sensor contributes to the downsizing of thecamera body. It should be noted that, in FIG. 3B, the photometry sensor9G is located at an upper central position on the eyepiece side of thepentagonal prism 5 as the normal light photometry sensor 9D in FIG. 3A.With this structure, the photometry sensitivity distribution can be madesymmetrical with respect to the center thereof, thereby the accuracy ofthe photometry sensor 9G can be improved.

[0177] The present disclosure relates to the subject matter contained inJapanese Patent Application No.2000-350732, filed on Nov. 17, 2000,which is expressly incorporated herein by reference in its entirety.

What is claimed is:
 1. A photometry device for a camera, comprising: anormal light sensor that has a plurality of photometry areas andperforms a photometry operation with respect to an object at each ofsaid plurality of photometry areas, said normal light sensor having aspectral sensitive characteristics close to those of a human eye; aplurality of colorimetric sensors for colorimetry capable of performingphotometry with respect to each of said plurality of photometry areas,said plurality of calorimetric sensors having different spectralsensitivity characteristics; a photometry value determining system thatdetermines an photometry value at each of said plurality of photometryareas in accordance with outputs of said normal light sensorcorresponding to said plurality of photometry areas; a calorimetriccompensation value determining system that determines a color of anobject at each of said plurality of photometry areas in accordance withthe outputs of said plurality of calorimetric sensors and determining acalorimetric compensation value based on the determined color; and anexposure value determining system that compensates for the photometryvalue determined by said photometry value determining system for each ofsaid plurality of photometry areas, and determines an exposure valuebased on the compensated photometry values, wherein said colorimetriccompensation value determining system determines different calorimetriccompensation values for different one of said plurality of photometryareas.
 2. The photometry device according to claim 1, wherein saidcolorimetric compensation value determining system determines thecolorimetric compensation values such that a calorimetric compensationvalue at a peripheral area of a photographing frame is smaller than thatof a central area of the photographing frame.
 3. The photometry deviceaccording to claim 1, wherein said colorimetric compensation valuedetermining system determines the colorimetric compensation values forthe plurality of photometry areas depending on a distance of eachphotometry area with respect to the center of a photographing frame. 4.The photometry device according to claim 3, wherein a colorimetriccompensation value at an area farther from the center of thephotographing frame is smaller than that at an area closer to the centerof the photographing frame.
 5. The photometry device according to claim1, wherein said calorimetric compensation value determining systemdetermines the colorimetric compensation values for the plurality ofphotometry areas depending on data intrinsic to a photographing lensthat forms an image of the object.
 6. The photometry device according toclaim 5, wherein the data intrinsic to the photographing lens includesat least one of a focal length of said photographing lens, an exit pupilposition of said photographing lens, and an open f-number of saidphotographing lens.
 7. The photometry device according to claim 5,wherein the data intrinsic to the photographing lens includes a focallength of said photographing lens, and wherein a colorimetriccompensation value has a greatest absolute value when the focal lengthis within a predetermined range, the colorimetric compensation valuebeing smaller when the focal length is greater or smaller than thepredetermined range.
 8. The photometry device according to claim 7,wherein the colorimetric compensation value is determined as a functionof the focal length.
 9. The photometry device according to claim 5,wherein the data intrinsic to the photographing lens includes an exitpupil position of said photographing lens, and wherein a colorimetriccompensation value has a greatest absolute value when the exit pupilposition is within a predetermined range, the colorimetric compensationvalue being smaller when the exit pupil position is on a front side orrear side with respect to the predetermined range.
 10. The photometrydevice according to claim 9, wherein the calorimetric compensation valueis determined as a function of the exit pupil position.
 11. Thephotometry device according to claim 5, wherein the data intrinsic tothe photographing lens includes an open f-number of said photographinglens, and wherein a colorimetric compensation value has a greatestabsolute value when the open f-number is within a predetermined range,the colorimetric compensation value being smaller when the open f-numberis smaller or greater than the predetermined range.
 12. The photometrydevice according to claim 11, wherein the colorimetric compensationvalue is determined as a function of the open f-number.
 13. Thephotometry device according to claim 1, wherein said colorimetriccompensation value determining system determines the calorimetriccompensation values for the plurality of photometry areas depending onan area corresponding to a part of an object on which a photographinglens is focused.
 14. The photometry device according to claim 13,wherein a calorimetric compensation value for an area corresponding to apart of the object on which the photographing lens is focused is greaterthan that for an area corresponding to another part of the object onwhich the photographing lens is not focused.
 15. The photometry deviceaccording to claim 1, wherein said exposure value determining system hasat least one of: a. a function of determining the exposure amount byperforming a divided photometry, based on the compensated photometryvalues, in accordance with a predetermined algorithm; b. a function ofdetermining the exposure amount by averaging the compensated photometryvalues for said plurality of photometry areas; c. a function ofdetermining the exposure amount by performing the center-weightedaveraging of the compensated photometry values; and d. a function ofdetermining the exposure amount by selecting one of the compensatedphotometry values corresponding to said plurality of areas.
 16. Thephotometry device according to claim 1, wherein said normal lightphotometry sensor and said plurality of colorimetric photometry sensorsare arranged on an eyepiece side of a pentagonal prism of a single lensreflex camera, at least said normal light photometry sensor beingarranged at an upper central portion of said pentagonal prism.